The present invention relates to the control of power trains (PT), in particular vehicle power trains, formed of at least one heat engine associated with an automatic or automated transmission, and possibly an electric traction machine.
More precisely, the invention relates to a method for controlling a vehicle power train comprising a heat engine connected to the transmission of the vehicle by a clutch controlled between an open position and a closed position of the transmission by a transmission computer, which exchanges information with the computer of the heat engine so as to close the air flap of the engine and disconnect the engine from the transmission when the vehicle is in motion.
This invention is applied preferably, but not exclusively, to any vehicle provided with the function of automatic engine stopping and restarting at standstill (stop and start) and with the function of transmission disconnection when the vehicle is in motion (coasting stop or sailing). This vehicle can advantageously be provided with an automatic or automated transmission integrated in a hybrid PTG.
The stop and start (S&S) system, which is present in numerous vehicles, significantly increases the number of times the heat engine is stopped and restarted during a journey. In some applications, referred to as “micro hybrids”, the addition of targeted electric power machines makes it possible to additionally introduce new functions intended to reduce further still the fuel consumption by stopping the engine as soon as there is no longer any need for traction, including when the vehicle is in motion. These new control strategies also result in a significant increase in the number of times the engine is shut down and restarted, which is almost trebled in this case. In the case of such vehicles, it is paramount that the shutdown and restart phases of the heat engine are virtually imperceptible to the users of the vehicle, i.e. the driver and passengers.